Virtual simulation system is commonly used for the training of aircraft, ship, vehicle or other heavy equipment control with sufficient reality to ensure that trainees become fully immersed in the training with a similar feel, appearance and movements as in actual operations.
In particular, a control stick (cyclic stick), side stick or footrest-type pedal should give trainees a realistic experience, so that they can feel as if they are actually operating the equipment. Hereafter, the controlling device which the trainee directly operates will be called the control stick.
During the actual piloting of an aircraft, when the control stick is manipulated there is a reaction force that occurs mechanically from each of the connected parts, the reaction force resulting from those moving parts is felt along with the reaction force from the aerodynamic force that is felt in the hand of the pilot. Such a reaction force is called control force. Accordingly, when training with virtual simulation systems, actuators are installed which apply artificial control force to the control sticks to feel the force.
As exiting techniques for actuators, there are Korea Public Patent No. 10-0851232, Korea Public Patent No. 10-2004-0092108, Korea Public Patent No. 10-2009-0061508, Korea Public Patent No. 10-2004-0018465 and others, the above existing techniques are configured to provide control force by mechanically connecting a motor with a control stick and controlling the motor by manipulating the control stick.
However, with a complicated configuration of the mechanical means of linking control sticks with the motor, the said existing techniques are complicated with the installation structure and cannot keep the motors horizontal, which brings about an unwanted force being applied to the motors by the weight of the control sticks or the means of linking. This problem keeps one from accurately adjusting the control force when manipulating the motors to apply the control force.
Moreover, Korea Public Patent No. 10-0851232, Korea Public Patent No. 10-2009-0061508 and Korea Public Patent No. 10-2004-0018465 include a reducer, a pulley or a belt in the means of linking, which generates errors in the transmission of force. Meaning that if one pair of gears engages configuring the reducer, a backlash would occur in between the gaps, and the pulley would around a belt becomes loose after extended use and would spin with no traction. In addition, Korea Public Patent No. 10-2004-0092108 is unaffected from the said problem because it connects the motor directly with the axis of rotation, but the because of the limits to the mounting structure of the motor it can only be applied to the virtual simulation system of limited application.
Also, the above existing techniques use the rotor of the rotation angle by sensing the location sensor or sensing the rotation angle by the built-in encoder, however, in order to set the absolute reference point only with a single position sensor, they should bear start-up time delay and inconvenience in that start-up time needs to be established with software whenever the virtual simulation system is turned on.
And though it is desirable to determine the magnitude of the force applied to an actuator as the control stick is manipulated so as to calculate the control force corresponding to the movement of the control stick, the said preceding arts do not include any force sensors and if one can be accommodated, the installation location is not proper and the magnitude of the force cannot be measured accurately because of their structure.